Description
BZX79-C20 20V Zener Voltage Regulator Diode
Product Overview
The BZX79-C20 is a high-reliability, 500mW Zener diode from onsemi, engineered for voltage regulation and transient suppression in compact electronic designs. Specifically calibrated to a nominal Zener voltage of 20V, this component is widely used in automotive, industrial, and consumer electronics to provide a stable voltage reference and protect sensitive circuitry from transient voltage spikes.
Housed in a small-form-factor DO-35 glass package, the BZX79-C20 is optimized for high-density PCB layouts where space is at a premium but high-performance regulation is required. Its sharp breakdown characteristic ensures a clean, reliable voltage clamp, making it an essential component for power management and signal-conditioning applications.
Key Features
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Precision 20V Regulation: Features a nominal Zener voltage of 20V with a tight tolerance, providing a dependable voltage benchmark for precision analog and digital circuits.
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Compact DO-35 Package: Designed for high-density mounting, the miniature glass package is ideal for modern, space-constrained electronic assemblies.
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500mW Power Dissipation: Provides robust thermal handling for low-to-medium power regulation tasks in a small physical footprint.
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Reliable Breakdown Performance: Optimized for a stable Zener knee, minimizing voltage ripple and ensuring consistent output even under variable load conditions.
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High Environmental Durability: Glass-passivated construction offers superior protection against environmental moisture and long-term thermal fatigue.
Technical Specifications
| Parameter | Specification |
| Component Type | Zener Voltage Regulator Diode |
| Nominal Zener Voltage ($V_Z$) | 20V |
| Power Dissipation ($P_D$) | 500mW |
| Test Current ($I_{ZT}$) | 5mA |
| Package Type | DO-35 (Axial Lead) |
| Tolerance | $\pm 5\%$ (C-suffix) |
| Operating Temperature | -65°C to +200°C |
Applications
The go-to solution for high-density 20V stabilization and transient suppression:
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Voltage Regulation: Ideal for creating stable 20V reference rails for precision instrumentation, sensor biasing, and analog-to-digital converters.
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Overvoltage Protection: Functions as a protective shunt to clamp transient voltage spikes, safeguarding sensitive components on 20V supply lines.
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Level Shifting: Effectively limits signals in control logic or signal-conditioning circuits to a maximum 20V threshold.
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General Power Management: A standard component for industrial control nodes and battery-operated equipment requiring precise voltage monitoring.

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